Numerous studies have demostrated that patients with affective disorders have cholinergic supersensitivity. The neuroendocrine challenge test to measure it employs pyridostigmine, which increase cholinergic tone in the hypothalamus, thereby releasing GH. Thee is a single study indicating that the patients who were probably bipolar and had brief improvement in their thought disorders after a trial with physostigmine, went on to be lithium responders. We wish to test the hypothesis that patients with affective disorders have cholinergic supersensitivity and determine if this supposed supersensitivity is a marker of response as well as certain personality traits, psychosensory experience, and the results of the challenge test.